×

Method for inverting reflection trace data from 3-D and 4-D seismic surveys and identifying subsurface fluid and pathways in and among hydrocarbon reservoirs based on impedance models

  • US 5,798,982 A
  • Filed: 04/29/1996
  • Issued: 08/25/1998
  • Est. Priority Date: 04/29/1996
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method for constructing one or more impedance models of a subsurface volume comprising:

  • (a) obtaining one or more 3-D seismic image of the subsurface volume from observed seismic reflection trace data derived from seismic surveys;

    (b) constructing an a priori impedance model of the subsurface volume based on estimated impedance trends within the subsurface volume, said a priori impedance model initially being substantially identical for each seismic image in recognition that basic lithologic structure remains substantially unchanged during the time interval between seismic surveys;

    (c) creating a model of the seismic reflection trace data for the subsurface volume based on the a priori impedance model by combining the a priori impedance model with a seismic source function or wavelet which is time/depth dependent throughout the subsurface region being modeled;

    (d) comparing the model and the observed seismic reflection trace data for each seismic image obtained and, if the model seismic reflection trace data and observed seismic reflection trace data vary by more than preselected tolerances, modifying the a priori impedance model corresponding to each seismic survey such that the variation between model and observed seismic reflection trace data will be decreased; and

    (e) iteratively repeating steps (c) and (d) until the model seismic reflection trace data and observed seismic reflection trace data variations are less than the preselected tolerances.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×